Geneva and Earl's chicks

Last year I bought 6 Sebright hens from TSC. 1 died the very next day, 1 unfortunately was attacked and killed for getting too close to my standard hens' eggs, 2 turned out to be roosters that couldn't get along with each other or my other roo, Earl, and I now have 2 beautiful Sebright hens. One of them, Geneva, has gone broody and is sitting on 10+ eggs. Since I gave my other roos to a friend with more land (and more hens ) about a week ago, I'm guessing the majority of the eggs would be fertilized by Earl, my Serema roo.
Two questions -
1. Does anyone have any experience with Serema-Sebright Cross chicks? I tried to google it and only found three instances of Serema-Sebright crosses, two had no info whatsoever, and the other person's chicks didn't survive , so not much info there either. Is this a particularly delicate cross? Should I do anything special for them?
2. I'm completely inexperienced with broody hens. I've owned chickens off and on for 6+ years and for some unknown reason have never had a hen go broody. I've read in some places that you need to move the hen and her eggs to a different location, such as a cage, and some say that is unnecessary. In my case if would be very difficult to move her - Geneva is sitting under our porch and there is only two ways to access her, one is by fireman crawling on my stomach about 20 ft. from the opening on one end to the other end of the porch, the other way is reaching through a tiny opening at the end where she's sitting. The opening closest to her is too small to get her out through, and I'm not too anxious to crawl 20 ft. on my stomach holding an angry hen. Is moving her really necessary? She's very safe where she is, and I can easily pass her food and water through the small opening. Also, when the chicks hatch, how old do they need to be before I re-home them? I don't want to separate them from Geneva too soon... Like I said, I have no experience with broody hens and I'm not sure how much the chicks depend on them and how attached they are to each other...